If you don't know what your doing I'd steer clear of RGH'ing mate. Pay someone to do it for you, its far less of a headache.
If you know what your doing it can be done in as little as 1 hour (depending on the system and nand size). You also have to have good qulaity equipment and parts too!
But I also know it can also take as long as 10-20 hours just to get it to Glitch, trying different wire lengths, caps, resistors, ecc files, ecc file creation programs, wire types, wire routes, RGH chip configurations and timing files. I'm no statistician but there must be a few 1000 or so combinations there lol.
My latest RGH2.0 took 10 hours to complete, tried just about everything listed above, then I was just about to quit when it gltiched
, also took another hour to finetune the boot time.
I used combo of Jrunner (for ecc file) and Multibuilder to create final image, jrunner image didnt work at all.
Coolrunner Rev C
C15 JP - Open
Cap - Open
R12 10ohm Resistor - Points 3-2 Closed
Cpu reset wire - 47.5CM, routed topside around CPU, past the ROL, around GPU and back to coolrunner.
No extra caps or resistors, sheilded wire didnt work.
Timing file - B
Xbox Type: Jasper 512mb
Results: Boots in approx 10 secs, xell in 5 secs.
I also know a bloke in syria who has been trying for over a month to glitch his xbox!